Emphasis on renewable energy sources has been increasing, for example, due to concerns for reducing fossil fuel greenhouse gas emissions, reducing dependence on imported oil, providing a substitute for fossil fuels, and providing basic chemical constituents to be used in other industries, such as chemical monomers for making plastics and the like. Lignocellulosic material represents a vast amount of renewable resources available in virtually every part of the world and has the potential to satisfy at least some of the needs for sources of fuels and chemicals.
Lignocellulosic material is biomass that contains lignin and cellulose. Lignocellulosic material includes, but is not limited to, wood, forestry waste, sawdust, straw, corn stover, sugarcane bagrasse, switchgrass, and other lignin and cellulose containing materials of biological origin. Lignin bonds to the cellulose and has a molecular structure of a cross-linked phenolic polymer having an abundance of aromatic rings. Lignin is generally present in lignocellulosic material in an amount of about 15 to about 30 percent by weight.
Lignocellulosic material when heated to about 300 to about 900° C. in the absence of air forms solid products, liquid products, and gaseous pyrolysis products. A condensable portion (vapors) of the gaseous pyrolysis product is condensed into biomass-derived pyrolysis oil. Biomass-derived pyrolysis oil is a complex, highly oxygenated organic liquid having properties that currently limit its direct utilization as a biofuel or as a basic chemical constituent. Conversion of biomass-derived pyrolysis oil into an aromatic hydrocarbon-rich product that is useful as a biofuel and/or a basic chemical constituent requires additional operations to fully or partially deoxygenate the biomass-derived pyrolysis oil. These additional operations are expensive and time-consuming.
Accordingly, it is desirable to provide methods and apparatuses for converting lignocellulosic material into an aromatic hydrocarbon-rich product that may be used as a biofuel and/or a basic chemical constituent. In addition, it is also desirable to provide methods and apparatuses for producing an aromatic hydrocarbon-rich product directly from lignocellulosic material without requiring additional operations that are expensive and time-consuming to fully or partially deoxygenate the product. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.